Oxytocin at Elective Cesarean Deliveries: A Dose-finding Study in Women With BMI ≥ 40kg/m2

Obesity Clinical Trial

Official title: Oxytocin at Elective Cesarean Deliveries: A Dose-finding Study in Women With BMI ≥ 40kg/m2

Status Completed

Clinical Trial Summary

Postpartum hemorrhage (PPH) due to uterine atony is a major cause of maternal morbidity and mortality. Uterotonic drugs are used to improve the muscle tone of the uterus after birth, and these are effective at reducing the incidence of PPH. Oxytocin is the most commonly used uterotonic drug to prevent and treat PPH. Large doses of this drug are asociated with adverse effects like low blood pressure, nausea, vomiting, abnormal heart rhythms and changes on ECG. Various international bodies recommend varying and high doses of oxytocin in elective cesarean sections. A study performed at Mount Sinai Hospital showed that a much smaller dose of oxytocin is required (ED95 being 0.35IU). However, most of the women included in this study were below a body mass index (BMI) of 40kg/m2.

The investigators seek to find the best dose for patients with a BMI>40kg/m2, as a higher dose may be needed in this population to contract the uterus adequately.

Clinical Trial Description

Postpartum hemorrhage (PPH) is one of the leading causes of death during childbirth and accounts for an estimated 140,000 deaths per year worldwide. The World Health Organization (WHO) recommends active management of the third stage of labor to prevent PPH, even in low risk patients. Prophylactic uterotonic drugs administered after delivery are the main element of active management of the third stage and have been demonstrated to reduce the incidence of PPH by up to 40%. Oxytocin is the most commonly used uterotonic in North America, however it has a very short duration of action and requires a continuous infusion to achieve sustained effect, with large doses associated with adverse effects like low blood pressure, nausea, vomiting, abnormal heart rhythms and changes on ECG.

The prevalence of obesity is increasing in young women and some studies have shown that obese women have higher rates of caesarean delivery compared to non-obese women. Other studies have demonstrated an increased risk of hemorrhage due to poor uterine tone in obese women. Laboratory studies show that BMI alone appears to contribute to blunted uterine muscle responses and therefore contraction responses to oxytocin in obese women.

Previous dose finding studies have excluded those women with a BMI of ≥40kgm2. Therefore, the investigators wish to perform a double-blind dose finding study using the biased coin up-and-down sequential allocation technique to determine the ED90 of oxytocin at cesarean section in those women with a BMI>40. ;

Related Conditions & MeSH terms

• Hemorrhage
• Obesity
• Postpartum Hemorrhage

• NCT number: NCT03957083
• Study type: Interventional
• Source: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
• Status: Completed
• Phase: N/A
• Start date: June 26, 2019
• Completion date: February 4, 2020